Extremely comfortable. I wear them under my helmet with integrated headphones when flying, and the regular foamies they provide are too hard and too big for my ears and the pressure from the helmet would make it almost painful, but those are perfect for me. Within seconds of placing them in my ears, I can feel them expand and block noises within maybe 30s. The expansion doesn't cause any pressure, and even with my helmet on, it is so comfortable. It's a lifesaver, I would have a hard time doing my job without those. The sound attenuation is very good, almost too good because of how quiet my headset becomes, I end up having to crank up the volume. It's good enough for walking next to functioning turboprop aircraft engines, so that's the important part. It comes in a ziploc bag inside the box; I thought it would just be a box with a front plastic, which I would prefer, but that works too. I can't recommend them enough, I wish those were the default foamies they provided us.